Preparation method of high-temperature normal-pressure color-fixing Raschel blanket

Abstract

The invention belongs to the technical field of textile, and particularly relates to a preparation method of a high-temperature normal-pressure color-fixing raschel blanket. The method comprises the procedures of warp knitting, pretreatment, printing, high-temperature and normal-pressure color fixing and aftertreatment. The process is characterized in that the high-temperature and normal-pressure color fixing procedure comprises the steps that the printed blanket is placed in a high-temperature and normal-pressure steamer, saturated steam is introduced, and the blanket is steamed for 15-25 minutes in a normal-pressure environment under the conditions that the temperature is 102-108 DEG C and the relative humidity is 85-98%. Optionally, the ageing temperature can be 105 + / -1 DEG C, the relative humidity can be 92 + / -2%, and the ageing time can be 20 minutes. According to the method, preferably, acrylic yarns are used as plush yarns, polyester filaments are used as ground yarns, and cationic dyes or disperse dyes are used for printing. By creating a specific high-temperature and high-humidity environment under normal pressure, the color fastness index of the obtained blanket reaches the level equivalent to that of a traditional high-temperature and high-pressure process, meanwhile, the equipment cost, the energy consumption and the safety risk are remarkably reduced, and the method is suitable for industrial production of the high-quality Raschel blanket.

Description

Technical Field

[0001] This invention belongs to the field of textile technology, specifically relating to a method for preparing a high-temperature, normal-pressure, color-fixed Raschel blanket. Background Technology

[0002] Raschel blankets, as a high-end textile, are highly favored in the market for their unique full pile, delicate feel, excellent warmth retention, and rich three-dimensional patterns. Their production process is complex, mainly including key steps such as warp knitting, pretreatment, printing, color fixing, and finishing. Among these, the color fixing process is the core link that determines the final color performance and various color fastness indicators of the blanket, directly affecting the product's quality grade and market value.

[0003] In existing technologies, the high-temperature, high-pressure steaming and color-fixing method is the most widely adopted and considered standard process for Raschel blankets made primarily of synthetic fibers such as acrylic. This method typically involves placing the printed blanket in a sealed, high-pressure steaming device. Saturated steam is introduced to maintain the internal environment at a pressure of 0.15 to 0.25 MPa, with the temperature correspondingly rising to 125 to 135°C. In this high-temperature, high-pressure environment, the movement of fiber macromolecular chains intensifies, micropores expand, and dye molecules gain a large amount of energy, significantly increasing their diffusion rate and migration. This allows them to penetrate deeper into the fiber and bond firmly with fiber molecules through van der Waals forces, hydrogen bonds, or ionic bonds. This process aims to ensure sufficient fixation of dye molecules to achieve excellent color fastness to washing, rubbing, and light.

[0004] However, this traditional high-temperature, high-pressure color-fixing process has a series of inherent and insurmountable drawbacks. The primary problem lies in its extremely demanding requirements for equipment. To achieve and maintain the high-pressure environment, the steaming machine must be designed as a sealed pressure vessel capable of withstanding enormous internal pressure. Its manufacturing materials, structural design, sealing performance, and safety control system must all meet special equipment standards. This results in a very high initial investment cost for the equipment, and subsequent maintenance costs are also a considerable ongoing expense.

[0005] Secondly, this process consumes a huge amount of energy. Heating the steam in the entire vaporization chamber from atmospheric pressure to the required high temperature and high pressure conditions requires a large amount of thermal energy. In addition, to ensure process stability, the system needs to continuously replenish steam to maintain constant parameters. The entire process is extremely energy-intensive and does not conform to the current development trend of green and low-carbon manufacturing.

[0006] Third, the production efficiency of this process is limited. Each color-fixing cycle includes long pressure increase and decrease phases. The pressure increase process must be carried out carefully and slowly to avoid excessive temperature and pressure fluctuations that could affect the uniformity of color fixation; after color fixation, the pressure decrease process must be even slower and smoother. If the pressure is decreased too quickly, the moisture inside the blanket will evaporate instantly, easily causing so-called "defects" or damaging the fiber structure. These necessary buffer times greatly extend the processing time of a single batch of products, restricting the improvement of overall production efficiency.

[0007] Finally, the high-pressure environment itself poses a significant safety hazard. Pressure vessels carry the potential risk of overpressure explosion, placing extremely high demands on the reliability of safety accessories such as safety valves and pressure gauges. Furthermore, operators must undergo rigorous training and strictly adhere to operating procedures; any negligence could lead to a serious safety accident.

[0008] To avoid the problems caused by high-pressure equipment, some technologies have attempted to use atmospheric pressure color fixing, that is, steaming treatment at a temperature below 100°C. However, due to the limited energy input, this method often results in insufficient activation of dye molecules, making it difficult for them to fully diffuse and fix into the fiber. The result is usually a low color fixation rate, especially the wet rubbing color fastness, which fails to meet the requirements of high-end products. At the same time, the increased dye hydrolysis affects the brightness and accuracy of the color, failing to meet the production needs of high-quality Raschel blankets.

[0009] Therefore, there has long been an urgent need in this field for an innovative color-fixing technology that can ensure Raschel blankets achieve excellent and stable color fastness performance, while effectively overcoming the many drawbacks of high-temperature and high-pressure processes, such as high cost, high energy consumption, low efficiency, and high safety risks. Summary of the Invention

[0010] The purpose of this invention is to provide a method for preparing a high-temperature, normal-pressure, color-fixed Raschel blanket.

[0011] To achieve the above objectives, the present invention provides the following technical solution:

[0012] A method for preparing a high-temperature, atmospheric-pressure, color-fixed Raschel blanket includes the following steps:

[0013] Warp knitting, pretreatment, printing, high-temperature and normal-pressure color fixing and posttreatment;

[0014] The high-temperature and normal-pressure color-fixing process is as follows: the printed blanket is placed in a high-temperature and normal-pressure steaming machine, saturated steam is introduced, and the blanket is steamed for 15-25 minutes at a temperature of 102-108℃ and a relative humidity of 85%-98% under normal pressure.

[0015] Furthermore, in the high-temperature and atmospheric-pressure color-fixing process, the evaporation temperature is 105±1℃.

[0016] Furthermore, in the high-temperature and normal-pressure color-fixing process, the relative humidity is 92±2%.

[0017] Furthermore, in the high-temperature and atmospheric-pressure color-fixing process, the evaporation time is 20 minutes.

[0018] Furthermore, the pretreatment process includes desizing, refining, bleaching, and drying and setting, wherein the drying and setting temperature is 130-150℃.

[0019] Furthermore, the post-processing steps include washing, soaping, softening, drying, ironing, combing, cutting, and binding; the softener used in the softening step is an amino silicone oil softener.

[0020] Furthermore, the amount of the amino silicone oil softener is 2-4% owf of the blanket weight.

[0021] Furthermore, in the warp knitting process, the plush yarn is made of acrylic yarn, and the base yarn is made of polyester filament.

[0022] Furthermore, the dyes used in the printing process are cationic dyes or disperse dyes.

[0023] A Raschel blanket, characterized in that it is prepared by a method for preparing high-temperature and normal-pressure color-fixed Raschel blankets.

[0024] The beneficial effects of this invention are as follows:

[0025] 1. This invention constructs a highly efficient color-fixing environment with energy input far exceeding that of traditional atmospheric pressure boiling water evaporation by precisely controlling the steam temperature at 102-108℃ and the relative humidity at 85%-98% under normal pressure, and maintaining the contact time for 15-25 minutes. This specific high-temperature and high-humidity condition provides dye molecules with sufficient activation energy to overcome the fiber adsorption energy barrier, greatly promoting the diffusion rate and migration depth of the dye from the fiber surface to the internal structure, achieving a full and firm bond between the dye and the fiber. The direct technical effect is that the resulting Raschel blanket, under stringent testing conditions such as dry rubbing, wet rubbing, and multiple washes, consistently meets and exceeds the first-class requirements of national quality standards for color fastness, especially the crucial wet rubbing fastness, achieving the same excellent level of quality as products obtained through current high-temperature and high-pressure processes.

[0026] 2. Since the core color-fixing process of this invention is carried out entirely under atmospheric pressure, the core requirement for the equipment changes from a sealed container capable of withstanding high pressure to an atmospheric pressure container capable of precisely controlling temperature and humidity. This eliminates the need for the equipment to be designed and manufactured according to pressure vessel standards, significantly reducing the stringent requirements for material selection, structural strength, welding processes, and safety certifications. The direct technical benefit is a substantial reduction in the manufacturing and procurement costs of the key equipment required for the color-fixing process, namely the high-temperature atmospheric pressure steaming machine. Simultaneously, the atmospheric pressure equipment has a relatively simple structure, and the frequency and complexity of its daily maintenance and repair are correspondingly reduced, thereby decreasing long-term maintenance expenses.

[0027] 3. This invention omits the two time-consuming stages of pressurization and depressurization, which are indispensable in traditional processes. The entire color-fixing process, from entering the constant temperature and humidity environment to completion, eliminates the need to wait for the pressure to slowly build up and safely release, thus making the process continuous and compact. Its direct technical effect is to shorten the processing time cycle required for a single batch of blanket products in the color-fixing process, increasing the equipment's capacity and turnover efficiency per unit time. Simultaneously, since there is no need to continuously compensate for large amounts of energy loss to maintain a high-pressure environment, the total steam consumption of the entire color-fixing process is effectively reduced, demonstrating excellent energy-saving effects.

[0028] 4. This invention eliminates the high-pressure environment, fundamentally removing all potential safety risks associated with it. The production equipment no longer falls under the category of special pressure equipment, completely avoiding the possibility of overpressure explosions due to equipment failure or improper operation. Its direct technical effect is a significant improvement in the inherent safety level of the production site, reducing the pressure on operators' special qualifications and operating procedures, making the production environment safer, management simpler, and effectively protecting the safety of personnel and property. Attached Figure Description

[0029] Figure 1 This is a process flow diagram for the preparation of a high-temperature, atmospheric-pressure color-fixing Raschel blanket. The flow diagram clearly illustrates the core process steps of this invention and visually compares the key innovation of this invention—high-temperature, atmospheric-pressure color fixing (102-108℃, 85-98% humidity, 15-25 min)—with the traditional high-pressure process, highlighting the advantages of this invention in simplifying the process and reducing equipment requirements. Detailed Implementation

[0030] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0031] Example 1

[0032] Using 3D acrylic yarn as the pile yarn and 75D / 36F polyester filament as the base yarn, the yarn is woven on a Raschel warp knitting machine to produce a product with a unit area weight of 350g / m². 2 Blanket fabric.

[0033] The resulting fabric was desized and refined in hot water at 95°C for 30 minutes. After desizing, the fabric was transferred to a bleaching solution and bleached at 110°C for 20 minutes. The fabric was then dried and set at 140°C.

[0034] The prepared cationic dye printing paste is used to print on the shaped greige fabric.

[0035] The printed fabric is fed into a high-temperature, atmospheric-pressure steaming machine. Saturated steam is continuously introduced into the steaming chamber, and the steam flow rate and the opening of the equipment's exhaust vent are controlled to maintain the temperature inside the chamber at a stable 105°C and the relative humidity at a stable 93%. The steaming is carried out continuously for 20 minutes under these atmospheric-pressure conditions.

[0036] After color fixing, the blanket is first washed twice in 40℃ warm water for 10 minutes each time. Then, it is soaped for 15 minutes in a 90℃ soaping solution containing 2g / L of soaping agent. Afterward, it is soaked in a 40℃ water bath with 3% amino silicone oil softener by weight of the blanket for 20 minutes for softening treatment. Finally, it undergoes drying, ironing, combing, cutting, and hemming processes to obtain the finished Raschel blanket.

[0037] Example 2

[0038] Using 5D acrylic yarn as the pile yarn and 100D / 48F polyester filament as the base yarn, the yarn is woven on a Raschel warp knitting machine to produce a product with a unit area mass of 420g / m². 2 Blanket fabric.

[0039] The resulting fabric was desized and refined in hot water at 98°C for 25 minutes. After desizing, the fabric was transferred to a bleaching solution and bleached at 105°C for 25 minutes. The fabric was then dried and set at 135°C.

[0040] The prepared disperse dye printing paste is used to print on the shaped greige fabric.

[0041] The printed fabric is fed into a high-temperature, atmospheric-pressure steaming machine. Saturated steam is continuously introduced into the steaming chamber, and the equipment is controlled to maintain the temperature inside the chamber at a stable 103°C and the relative humidity at a stable 88%. The steaming is carried out continuously for 22 minutes under these atmospheric pressure conditions.

[0042] After color fixing, the blanket is first washed twice in 35℃ warm water for 12 minutes each time. Then, it is soaped for 18 minutes in an 88℃ soaping solution containing 1.5g / L soap detergent. Afterward, it is soaked in a 35℃ water bath with 2.5% amino silicone oil softener by weight of the blanket for 25 minutes for softening treatment. Finally, it undergoes drying, ironing, combing, cutting, and hemming processes to obtain the finished Raschel blanket.

[0043] Example 3

[0044] Using 4D acrylic yarn as the pile yarn and 90D / 72F polyester filament as the base yarn, the yarn is woven on a Raschel warp knitting machine to produce a product with a unit area mass of 380g / m². 2 Blanket fabric.

[0045] The resulting fabric was desized and refined in hot water at 90°C for 35 minutes. After desizing, the fabric was transferred to a bleaching solution and bleached at 115°C for 18 minutes. The fabric was then dried and set at 145°C.

[0046] The prepared cationic dye printing paste is used to print on the shaped greige fabric.

[0047] The printed fabric is fed into a high-temperature, atmospheric-pressure steaming machine. Saturated steam is continuously introduced into the steaming chamber, and the equipment is controlled to maintain a stable temperature of 107°C and a stable relative humidity of 96%. The steaming is carried out continuously for 18 minutes under these atmospheric-pressure conditions.

[0048] After color fixing, the blanket is first washed twice in 45℃ warm water, 8 minutes each time. Then, it is soaped for 12 minutes in a 92℃ soaping solution containing 2.5g / L soap detergent. Afterward, it is soaked in a 45℃ water bath with 3.5% amino silicone oil softener by weight of the blanket for 18 minutes for softening treatment. Finally, it undergoes drying, ironing, combing, cutting, and hemming processes to obtain the finished Raschel blanket.

[0049] Comparative Example 1

[0050] Except for the color fixing process, the other steps are exactly the same as in Example 1. The color fixing process is changed to: placing the printed blank in a high temperature and high pressure steamer and steaming it for 25 minutes under a pressure of 0.18 MPa and a temperature of 128°C.

[0051] Comparative Example 2

[0052] Except for the color fixing process, the other steps are exactly the same as in Example 1. The color fixing process is changed to: placing the printed blank in an atmospheric pressure steamer and steaming it for 25 minutes at a temperature of 98°C and a relative humidity of 85%.

[0053] Performance testing

[0054] The color fastness of the finished blankets obtained in Examples 1-3 and Comparative Examples 1-2 was tested, and the results are shown in the table below:

[0055] Table 1: Performance Data of Examples and Comparative Examples

[0056]

[0057] Test results show that the Raschel blankets prepared using the method described in this invention (Examples 1-3) all meet or exceed the requirements for first-class products in national standards GB / T3920-2008 and GB / T3921-2008 in terms of color fastness. The effect is not significantly different from the traditional high-temperature and high-pressure process (Comparative Example 1), and is significantly superior to the low-temperature and normal-pressure process (Comparative Example 2). This proves that this invention successfully achieves a color-fixing effect comparable to high-pressure processes by fixing the color under specific high-temperature, high-humidity, and normal-pressure conditions. A process flow chart for preparing a high-temperature and normal-pressure color-fixed Raschel blanket is shown below. Figure 1 .

[0058] Matters not covered in this invention are common knowledge.

[0059] The above description is merely a preferred embodiment of the present invention; however, the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and its improved concept, should be covered within the scope of protection of the present invention.

Claims

1. A method for preparing a high-temperature, normal-pressure, color-fixed Raschel blanket, characterized in that, Includes the following steps: Warp knitting, pretreatment, printing, high-temperature and normal-pressure color fixing and posttreatment; The high-temperature and normal-pressure color-fixing process is as follows: the printed blanket is placed in a high-temperature and normal-pressure steaming machine, saturated steam is introduced, and it is steamed for 15-25 minutes in a normal-pressure environment at a temperature of 102-108℃ and a relative humidity of 85%-98%.

2. The method for preparing high-temperature, atmospheric-pressure, color-fixed Raschel blanket according to claim 1, characterized in that, In the high-temperature and normal-pressure color-fixing process, the evaporation temperature is 105±1℃.

3. The method for preparing high-temperature, atmospheric-pressure, color-fixed Raschel blanket according to claim 1, characterized in that, In the high-temperature and normal-pressure color-fixing process, the relative humidity is 92±2%.

4. The method for preparing high-temperature, atmospheric-pressure, color-fixed Raschel blanket according to claim 1, characterized in that, In the high-temperature and normal-pressure color-fixing process, the steaming time is 20 minutes.

5. The method for preparing high-temperature, atmospheric-pressure, color-fixed Raschel blanket according to claim 1, characterized in that, The pretreatment process includes desizing, refining, bleaching and drying, with the drying temperature being 130-150℃.

6. The method for preparing high-temperature, atmospheric-pressure fixed-color Raschel blanket according to claim 1, characterized in that, The post-processing steps include washing, soaping, softening, drying, ironing, combing, cutting, and binding; the softener used in the softening step is an amino silicone oil softener.

7. The method for preparing high-temperature, atmospheric-pressure, color-fixed Raschel blanket according to claim 6, characterized in that, The amount of the amino silicone oil softener used is 2-4% owf of the blanket weight.

8. The method for preparing high-temperature, atmospheric-pressure, color-fixed Raschel blanket according to claim 1, characterized in that, In the warp knitting process, the plush yarn is made of acrylic yarn, and the base yarn is made of polyester filament.

9. The method for preparing high-temperature, atmospheric-pressure, color-fixed Raschel blanket according to claim 1, characterized in that, The dyes used in the printing process are cationic dyes or disperse dyes.

10. A Raschel blanket, characterized in that, It is prepared by the method of any one of claims 1 to 9 for preparing high temperature and normal pressure fixed color Raschel blanket.

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